Join us at The Bloomsbury this May and toast to King Charles III with our royal take on an espresso martini: the King Charles Espresso. To celebrate His Majesty’s passion for sustainability — as well as our own — the cocktail features a delicious homemade coffee kombucha that reuses coffee grounds.

We asked cocktail connoisseur, The Coral Room and Dalloway Terrace ’s General Manager, Gio Spezziga, for his kombucha recipe, so you can try it at home.

Recipe: Homemade Coffee Kombucha

Makes approximately 2 litres

Ingredients:

30g unrefined sugar

700g used coffee grounds

300ml mature kombucha scoby

Method:

• Measure two litres of just-boiled water into a heatproof glass or ceramic jug, stir in the sugar and spent coffee grounds, and leave to infuse overnight.

• The next day, strain through a non-metallic sieve into a fermentation jar, add the kombucha and gently float the scoby on top.

• Cover the jar with a clean tea towel, secure it in place with a rubber band or string, then put the jar in a warm, roughly 20C spot out of direct sunlight.

• It will take between 3-14 days to ferment.

• Strain into sterilised bottles, keeping back 300ml of backslop for the next batch, and store in the fridge, or leave to ferment a second time, which will carbonate the drink.

Discover all our coronation cocktails, available at The Kensington, The Marylebone and The Bloomsbury in London and The Bristol on Bristol’s Harbourside.